2 * Copyright (c) International Business Machines Corp., 2006
3 * Copyright (c) Nokia Corporation, 2007
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
13 * the GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License
16 * along with this program; if not, write to the Free Software
17 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
19 * Author: Artem Bityutskiy (Битюцкий Артём),
24 * This file includes UBI initialization and building of UBI devices.
26 * When UBI is initialized, it attaches all the MTD devices specified as the
27 * module load parameters or the kernel boot parameters. If MTD devices were
28 * specified, UBI does not attach any MTD device, but it is possible to do
29 * later using the "UBI control device".
32 #include <linux/err.h>
33 #include <linux/module.h>
34 #include <linux/moduleparam.h>
35 #include <linux/stringify.h>
36 #include <linux/namei.h>
37 #include <linux/stat.h>
38 #include <linux/miscdevice.h>
39 #include <linux/mtd/partitions.h>
40 #include <linux/log2.h>
41 #include <linux/kthread.h>
42 #include <linux/kernel.h>
43 #include <linux/slab.h>
46 /* Maximum length of the 'mtd=' parameter */
47 #define MTD_PARAM_LEN_MAX 64
49 /* Maximum number of comma-separated items in the 'mtd=' parameter */
50 #define MTD_PARAM_MAX_COUNT 2
52 /* Maximum value for the number of bad PEBs per 1024 PEBs */
53 #define MAX_MTD_UBI_BEB_LIMIT 768
55 #ifdef CONFIG_MTD_UBI_MODULE
56 #define ubi_is_module() 1
58 #define ubi_is_module() 0
62 * struct mtd_dev_param - MTD device parameter description data structure.
63 * @name: MTD character device node path, MTD device name, or MTD device number
65 * @vid_hdr_offs: VID header offset
67 struct mtd_dev_param {
68 char name[MTD_PARAM_LEN_MAX];
72 /* Numbers of elements set in the @mtd_dev_param array */
73 static int __initdata mtd_devs;
75 /* MTD devices specification parameters */
76 static struct mtd_dev_param __initdata mtd_dev_param[UBI_MAX_DEVICES];
78 /* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
79 struct class *ubi_class;
81 /* Slab cache for wear-leveling entries */
82 struct kmem_cache *ubi_wl_entry_slab;
84 /* UBI control character device */
85 static struct miscdevice ubi_ctrl_cdev = {
86 .minor = MISC_DYNAMIC_MINOR,
88 .fops = &ubi_ctrl_cdev_operations,
91 /* All UBI devices in system */
92 static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
94 /* Serializes UBI devices creations and removals */
95 DEFINE_MUTEX(ubi_devices_mutex);
97 /* Protects @ubi_devices and @ubi->ref_count */
98 static DEFINE_SPINLOCK(ubi_devices_lock);
100 /* "Show" method for files in '/<sysfs>/class/ubi/' */
101 static ssize_t ubi_version_show(struct class *class,
102 struct class_attribute *attr, char *buf)
104 return sprintf(buf, "%d\n", UBI_VERSION);
107 /* UBI version attribute ('/<sysfs>/class/ubi/version') */
108 static struct class_attribute ubi_version =
109 __ATTR(version, S_IRUGO, ubi_version_show, NULL);
111 static ssize_t dev_attribute_show(struct device *dev,
112 struct device_attribute *attr, char *buf);
114 /* UBI device attributes (correspond to files in '/<sysfs>/class/ubi/ubiX') */
115 static struct device_attribute dev_eraseblock_size =
116 __ATTR(eraseblock_size, S_IRUGO, dev_attribute_show, NULL);
117 static struct device_attribute dev_avail_eraseblocks =
118 __ATTR(avail_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
119 static struct device_attribute dev_total_eraseblocks =
120 __ATTR(total_eraseblocks, S_IRUGO, dev_attribute_show, NULL);
121 static struct device_attribute dev_volumes_count =
122 __ATTR(volumes_count, S_IRUGO, dev_attribute_show, NULL);
123 static struct device_attribute dev_max_ec =
124 __ATTR(max_ec, S_IRUGO, dev_attribute_show, NULL);
125 static struct device_attribute dev_reserved_for_bad =
126 __ATTR(reserved_for_bad, S_IRUGO, dev_attribute_show, NULL);
127 static struct device_attribute dev_bad_peb_count =
128 __ATTR(bad_peb_count, S_IRUGO, dev_attribute_show, NULL);
129 static struct device_attribute dev_max_vol_count =
130 __ATTR(max_vol_count, S_IRUGO, dev_attribute_show, NULL);
131 static struct device_attribute dev_min_io_size =
132 __ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
133 static struct device_attribute dev_bgt_enabled =
134 __ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
135 static struct device_attribute dev_mtd_num =
136 __ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
139 * ubi_volume_notify - send a volume change notification.
140 * @ubi: UBI device description object
141 * @vol: volume description object of the changed volume
142 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
144 * This is a helper function which notifies all subscribers about a volume
145 * change event (creation, removal, re-sizing, re-naming, updating). Returns
146 * zero in case of success and a negative error code in case of failure.
148 int ubi_volume_notify(struct ubi_device *ubi, struct ubi_volume *vol, int ntype)
150 struct ubi_notification nt;
152 ubi_do_get_device_info(ubi, &nt.di);
153 ubi_do_get_volume_info(ubi, vol, &nt.vi);
154 return blocking_notifier_call_chain(&ubi_notifiers, ntype, &nt);
158 * ubi_notify_all - send a notification to all volumes.
159 * @ubi: UBI device description object
160 * @ntype: notification type to send (%UBI_VOLUME_ADDED, etc)
161 * @nb: the notifier to call
163 * This function walks all volumes of UBI device @ubi and sends the @ntype
164 * notification for each volume. If @nb is %NULL, then all registered notifiers
165 * are called, otherwise only the @nb notifier is called. Returns the number of
166 * sent notifications.
168 int ubi_notify_all(struct ubi_device *ubi, int ntype, struct notifier_block *nb)
170 struct ubi_notification nt;
173 ubi_do_get_device_info(ubi, &nt.di);
175 mutex_lock(&ubi->device_mutex);
176 for (i = 0; i < ubi->vtbl_slots; i++) {
178 * Since the @ubi->device is locked, and we are not going to
179 * change @ubi->volumes, we do not have to lock
180 * @ubi->volumes_lock.
182 if (!ubi->volumes[i])
185 ubi_do_get_volume_info(ubi, ubi->volumes[i], &nt.vi);
187 nb->notifier_call(nb, ntype, &nt);
189 blocking_notifier_call_chain(&ubi_notifiers, ntype,
193 mutex_unlock(&ubi->device_mutex);
199 * ubi_enumerate_volumes - send "add" notification for all existing volumes.
200 * @nb: the notifier to call
202 * This function walks all UBI devices and volumes and sends the
203 * %UBI_VOLUME_ADDED notification for each volume. If @nb is %NULL, then all
204 * registered notifiers are called, otherwise only the @nb notifier is called.
205 * Returns the number of sent notifications.
207 int ubi_enumerate_volumes(struct notifier_block *nb)
212 * Since the @ubi_devices_mutex is locked, and we are not going to
213 * change @ubi_devices, we do not have to lock @ubi_devices_lock.
215 for (i = 0; i < UBI_MAX_DEVICES; i++) {
216 struct ubi_device *ubi = ubi_devices[i];
220 count += ubi_notify_all(ubi, UBI_VOLUME_ADDED, nb);
227 * ubi_get_device - get UBI device.
228 * @ubi_num: UBI device number
230 * This function returns UBI device description object for UBI device number
231 * @ubi_num, or %NULL if the device does not exist. This function increases the
232 * device reference count to prevent removal of the device. In other words, the
233 * device cannot be removed if its reference count is not zero.
235 struct ubi_device *ubi_get_device(int ubi_num)
237 struct ubi_device *ubi;
239 spin_lock(&ubi_devices_lock);
240 ubi = ubi_devices[ubi_num];
242 ubi_assert(ubi->ref_count >= 0);
244 get_device(&ubi->dev);
246 spin_unlock(&ubi_devices_lock);
252 * ubi_put_device - drop an UBI device reference.
253 * @ubi: UBI device description object
255 void ubi_put_device(struct ubi_device *ubi)
257 spin_lock(&ubi_devices_lock);
259 put_device(&ubi->dev);
260 spin_unlock(&ubi_devices_lock);
264 * ubi_get_by_major - get UBI device by character device major number.
265 * @major: major number
267 * This function is similar to 'ubi_get_device()', but it searches the device
268 * by its major number.
270 struct ubi_device *ubi_get_by_major(int major)
273 struct ubi_device *ubi;
275 spin_lock(&ubi_devices_lock);
276 for (i = 0; i < UBI_MAX_DEVICES; i++) {
277 ubi = ubi_devices[i];
278 if (ubi && MAJOR(ubi->cdev.dev) == major) {
279 ubi_assert(ubi->ref_count >= 0);
281 get_device(&ubi->dev);
282 spin_unlock(&ubi_devices_lock);
286 spin_unlock(&ubi_devices_lock);
292 * ubi_major2num - get UBI device number by character device major number.
293 * @major: major number
295 * This function searches UBI device number object by its major number. If UBI
296 * device was not found, this function returns -ENODEV, otherwise the UBI device
297 * number is returned.
299 int ubi_major2num(int major)
301 int i, ubi_num = -ENODEV;
303 spin_lock(&ubi_devices_lock);
304 for (i = 0; i < UBI_MAX_DEVICES; i++) {
305 struct ubi_device *ubi = ubi_devices[i];
307 if (ubi && MAJOR(ubi->cdev.dev) == major) {
308 ubi_num = ubi->ubi_num;
312 spin_unlock(&ubi_devices_lock);
317 /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
318 static ssize_t dev_attribute_show(struct device *dev,
319 struct device_attribute *attr, char *buf)
322 struct ubi_device *ubi;
325 * The below code looks weird, but it actually makes sense. We get the
326 * UBI device reference from the contained 'struct ubi_device'. But it
327 * is unclear if the device was removed or not yet. Indeed, if the
328 * device was removed before we increased its reference count,
329 * 'ubi_get_device()' will return -ENODEV and we fail.
331 * Remember, 'struct ubi_device' is freed in the release function, so
332 * we still can use 'ubi->ubi_num'.
334 ubi = container_of(dev, struct ubi_device, dev);
335 ubi = ubi_get_device(ubi->ubi_num);
339 if (attr == &dev_eraseblock_size)
340 ret = sprintf(buf, "%d\n", ubi->leb_size);
341 else if (attr == &dev_avail_eraseblocks)
342 ret = sprintf(buf, "%d\n", ubi->avail_pebs);
343 else if (attr == &dev_total_eraseblocks)
344 ret = sprintf(buf, "%d\n", ubi->good_peb_count);
345 else if (attr == &dev_volumes_count)
346 ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
347 else if (attr == &dev_max_ec)
348 ret = sprintf(buf, "%d\n", ubi->max_ec);
349 else if (attr == &dev_reserved_for_bad)
350 ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
351 else if (attr == &dev_bad_peb_count)
352 ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
353 else if (attr == &dev_max_vol_count)
354 ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
355 else if (attr == &dev_min_io_size)
356 ret = sprintf(buf, "%d\n", ubi->min_io_size);
357 else if (attr == &dev_bgt_enabled)
358 ret = sprintf(buf, "%d\n", ubi->thread_enabled);
359 else if (attr == &dev_mtd_num)
360 ret = sprintf(buf, "%d\n", ubi->mtd->index);
368 static void dev_release(struct device *dev)
370 struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
376 * ubi_sysfs_init - initialize sysfs for an UBI device.
377 * @ubi: UBI device description object
378 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
381 * This function returns zero in case of success and a negative error code in
384 static int ubi_sysfs_init(struct ubi_device *ubi, int *ref)
388 ubi->dev.release = dev_release;
389 ubi->dev.devt = ubi->cdev.dev;
390 ubi->dev.class = ubi_class;
391 dev_set_name(&ubi->dev, UBI_NAME_STR"%d", ubi->ubi_num);
392 err = device_register(&ubi->dev);
397 err = device_create_file(&ubi->dev, &dev_eraseblock_size);
400 err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
403 err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
406 err = device_create_file(&ubi->dev, &dev_volumes_count);
409 err = device_create_file(&ubi->dev, &dev_max_ec);
412 err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
415 err = device_create_file(&ubi->dev, &dev_bad_peb_count);
418 err = device_create_file(&ubi->dev, &dev_max_vol_count);
421 err = device_create_file(&ubi->dev, &dev_min_io_size);
424 err = device_create_file(&ubi->dev, &dev_bgt_enabled);
427 err = device_create_file(&ubi->dev, &dev_mtd_num);
432 * ubi_sysfs_close - close sysfs for an UBI device.
433 * @ubi: UBI device description object
435 static void ubi_sysfs_close(struct ubi_device *ubi)
437 device_remove_file(&ubi->dev, &dev_mtd_num);
438 device_remove_file(&ubi->dev, &dev_bgt_enabled);
439 device_remove_file(&ubi->dev, &dev_min_io_size);
440 device_remove_file(&ubi->dev, &dev_max_vol_count);
441 device_remove_file(&ubi->dev, &dev_bad_peb_count);
442 device_remove_file(&ubi->dev, &dev_reserved_for_bad);
443 device_remove_file(&ubi->dev, &dev_max_ec);
444 device_remove_file(&ubi->dev, &dev_volumes_count);
445 device_remove_file(&ubi->dev, &dev_total_eraseblocks);
446 device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
447 device_remove_file(&ubi->dev, &dev_eraseblock_size);
448 device_unregister(&ubi->dev);
452 * kill_volumes - destroy all user volumes.
453 * @ubi: UBI device description object
455 static void kill_volumes(struct ubi_device *ubi)
459 for (i = 0; i < ubi->vtbl_slots; i++)
461 ubi_free_volume(ubi, ubi->volumes[i]);
465 * uif_init - initialize user interfaces for an UBI device.
466 * @ubi: UBI device description object
467 * @ref: set to %1 on exit in case of failure if a reference to @ubi->dev was
468 * taken, otherwise set to %0
470 * This function initializes various user interfaces for an UBI device. If the
471 * initialization fails at an early stage, this function frees all the
472 * resources it allocated, returns an error, and @ref is set to %0. However,
473 * if the initialization fails after the UBI device was registered in the
474 * driver core subsystem, this function takes a reference to @ubi->dev, because
475 * otherwise the release function ('dev_release()') would free whole @ubi
476 * object. The @ref argument is set to %1 in this case. The caller has to put
479 * This function returns zero in case of success and a negative error code in
482 static int uif_init(struct ubi_device *ubi, int *ref)
488 sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
491 * Major numbers for the UBI character devices are allocated
492 * dynamically. Major numbers of volume character devices are
493 * equivalent to ones of the corresponding UBI character device. Minor
494 * numbers of UBI character devices are 0, while minor numbers of
495 * volume character devices start from 1. Thus, we allocate one major
496 * number and ubi->vtbl_slots + 1 minor numbers.
498 err = alloc_chrdev_region(&dev, 0, ubi->vtbl_slots + 1, ubi->ubi_name);
500 ubi_err("cannot register UBI character devices");
504 ubi_assert(MINOR(dev) == 0);
505 cdev_init(&ubi->cdev, &ubi_cdev_operations);
506 dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
507 ubi->cdev.owner = THIS_MODULE;
509 err = cdev_add(&ubi->cdev, dev, 1);
511 ubi_err("cannot add character device");
515 err = ubi_sysfs_init(ubi, ref);
519 for (i = 0; i < ubi->vtbl_slots; i++)
520 if (ubi->volumes[i]) {
521 err = ubi_add_volume(ubi, ubi->volumes[i]);
523 ubi_err("cannot add volume %d", i);
534 get_device(&ubi->dev);
535 ubi_sysfs_close(ubi);
536 cdev_del(&ubi->cdev);
538 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
539 ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
544 * uif_close - close user interfaces for an UBI device.
545 * @ubi: UBI device description object
547 * Note, since this function un-registers UBI volume device objects (@vol->dev),
548 * the memory allocated voe the volumes is freed as well (in the release
551 static void uif_close(struct ubi_device *ubi)
554 ubi_sysfs_close(ubi);
555 cdev_del(&ubi->cdev);
556 unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
560 * ubi_free_internal_volumes - free internal volumes.
561 * @ubi: UBI device description object
563 void ubi_free_internal_volumes(struct ubi_device *ubi)
567 for (i = ubi->vtbl_slots;
568 i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
569 kfree(ubi->volumes[i]->eba_tbl);
570 kfree(ubi->volumes[i]);
574 static int get_bad_peb_limit(const struct ubi_device *ubi, int max_beb_per1024)
576 int limit, device_pebs;
577 uint64_t device_size;
579 if (!max_beb_per1024)
583 * Here we are using size of the entire flash chip and
584 * not just the MTD partition size because the maximum
585 * number of bad eraseblocks is a percentage of the
586 * whole device and bad eraseblocks are not fairly
587 * distributed over the flash chip. So the worst case
588 * is that all the bad eraseblocks of the chip are in
589 * the MTD partition we are attaching (ubi->mtd).
591 device_size = mtd_get_device_size(ubi->mtd);
592 device_pebs = mtd_div_by_eb(device_size, ubi->mtd);
593 limit = mult_frac(device_pebs, max_beb_per1024, 1024);
596 if (mult_frac(limit, 1024, max_beb_per1024) < device_pebs)
603 * io_init - initialize I/O sub-system for a given UBI device.
604 * @ubi: UBI device description object
605 * @max_beb_per1024: maximum expected number of bad PEB per 1024 PEBs
607 * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
609 * o EC header is always at offset zero - this cannot be changed;
610 * o VID header starts just after the EC header at the closest address
611 * aligned to @io->hdrs_min_io_size;
612 * o data starts just after the VID header at the closest address aligned to
615 * This function returns zero in case of success and a negative error code in
618 static int io_init(struct ubi_device *ubi, int max_beb_per1024)
620 if (ubi->mtd->numeraseregions != 0) {
622 * Some flashes have several erase regions. Different regions
623 * may have different eraseblock size and other
624 * characteristics. It looks like mostly multi-region flashes
625 * have one "main" region and one or more small regions to
626 * store boot loader code or boot parameters or whatever. I
627 * guess we should just pick the largest region. But this is
630 ubi_err("multiple regions, not implemented");
634 if (ubi->vid_hdr_offset < 0)
638 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
639 * physical eraseblocks maximum.
642 ubi->peb_size = ubi->mtd->erasesize;
643 ubi->peb_count = mtd_div_by_eb(ubi->mtd->size, ubi->mtd);
644 ubi->flash_size = ubi->mtd->size;
646 if (mtd_can_have_bb(ubi->mtd)) {
647 ubi->bad_allowed = 1;
648 ubi->bad_peb_limit = get_bad_peb_limit(ubi, max_beb_per1024);
651 if (ubi->mtd->type == MTD_NORFLASH) {
652 ubi_assert(ubi->mtd->writesize == 1);
656 ubi->min_io_size = ubi->mtd->writesize;
657 ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
660 * Make sure minimal I/O unit is power of 2. Note, there is no
661 * fundamental reason for this assumption. It is just an optimization
662 * which allows us to avoid costly division operations.
664 if (!is_power_of_2(ubi->min_io_size)) {
665 ubi_err("min. I/O unit (%d) is not power of 2",
670 ubi_assert(ubi->hdrs_min_io_size > 0);
671 ubi_assert(ubi->hdrs_min_io_size <= ubi->min_io_size);
672 ubi_assert(ubi->min_io_size % ubi->hdrs_min_io_size == 0);
674 ubi->max_write_size = ubi->mtd->writebufsize;
676 * Maximum write size has to be greater or equivalent to min. I/O
677 * size, and be multiple of min. I/O size.
679 if (ubi->max_write_size < ubi->min_io_size ||
680 ubi->max_write_size % ubi->min_io_size ||
681 !is_power_of_2(ubi->max_write_size)) {
682 ubi_err("bad write buffer size %d for %d min. I/O unit",
683 ubi->max_write_size, ubi->min_io_size);
687 /* Calculate default aligned sizes of EC and VID headers */
688 ubi->ec_hdr_alsize = ALIGN(UBI_EC_HDR_SIZE, ubi->hdrs_min_io_size);
689 ubi->vid_hdr_alsize = ALIGN(UBI_VID_HDR_SIZE, ubi->hdrs_min_io_size);
691 dbg_msg("min_io_size %d", ubi->min_io_size);
692 dbg_msg("max_write_size %d", ubi->max_write_size);
693 dbg_msg("hdrs_min_io_size %d", ubi->hdrs_min_io_size);
694 dbg_msg("ec_hdr_alsize %d", ubi->ec_hdr_alsize);
695 dbg_msg("vid_hdr_alsize %d", ubi->vid_hdr_alsize);
697 if (ubi->vid_hdr_offset == 0)
699 ubi->vid_hdr_offset = ubi->vid_hdr_aloffset =
702 ubi->vid_hdr_aloffset = ubi->vid_hdr_offset &
703 ~(ubi->hdrs_min_io_size - 1);
704 ubi->vid_hdr_shift = ubi->vid_hdr_offset -
705 ubi->vid_hdr_aloffset;
708 /* Similar for the data offset */
709 ubi->leb_start = ubi->vid_hdr_offset + UBI_VID_HDR_SIZE;
710 ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
712 dbg_msg("vid_hdr_offset %d", ubi->vid_hdr_offset);
713 dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
714 dbg_msg("vid_hdr_shift %d", ubi->vid_hdr_shift);
715 dbg_msg("leb_start %d", ubi->leb_start);
717 /* The shift must be aligned to 32-bit boundary */
718 if (ubi->vid_hdr_shift % 4) {
719 ubi_err("unaligned VID header shift %d",
725 if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
726 ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
727 ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
728 ubi->leb_start & (ubi->min_io_size - 1)) {
729 ubi_err("bad VID header (%d) or data offsets (%d)",
730 ubi->vid_hdr_offset, ubi->leb_start);
735 * Set maximum amount of physical erroneous eraseblocks to be 10%.
736 * Erroneous PEB are those which have read errors.
738 ubi->max_erroneous = ubi->peb_count / 10;
739 if (ubi->max_erroneous < 16)
740 ubi->max_erroneous = 16;
741 dbg_msg("max_erroneous %d", ubi->max_erroneous);
744 * It may happen that EC and VID headers are situated in one minimal
745 * I/O unit. In this case we can only accept this UBI image in
748 if (ubi->vid_hdr_offset + UBI_VID_HDR_SIZE <= ubi->hdrs_min_io_size) {
749 ubi_warn("EC and VID headers are in the same minimal I/O unit, "
750 "switch to read-only mode");
754 ubi->leb_size = ubi->peb_size - ubi->leb_start;
756 if (!(ubi->mtd->flags & MTD_WRITEABLE)) {
757 ubi_msg("MTD device %d is write-protected, attach in "
758 "read-only mode", ubi->mtd->index);
762 ubi_msg("physical eraseblock size: %d bytes (%d KiB)",
763 ubi->peb_size, ubi->peb_size >> 10);
764 ubi_msg("logical eraseblock size: %d bytes", ubi->leb_size);
765 ubi_msg("smallest flash I/O unit: %d", ubi->min_io_size);
766 if (ubi->hdrs_min_io_size != ubi->min_io_size)
767 ubi_msg("sub-page size: %d",
768 ubi->hdrs_min_io_size);
769 ubi_msg("VID header offset: %d (aligned %d)",
770 ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
771 ubi_msg("data offset: %d", ubi->leb_start);
774 * Note, ideally, we have to initialize @ubi->bad_peb_count here. But
775 * unfortunately, MTD does not provide this information. We should loop
776 * over all physical eraseblocks and invoke mtd->block_is_bad() for
777 * each physical eraseblock. So, we leave @ubi->bad_peb_count
778 * uninitialized so far.
785 * autoresize - re-size the volume which has the "auto-resize" flag set.
786 * @ubi: UBI device description object
787 * @vol_id: ID of the volume to re-size
789 * This function re-sizes the volume marked by the %UBI_VTBL_AUTORESIZE_FLG in
790 * the volume table to the largest possible size. See comments in ubi-header.h
791 * for more description of the flag. Returns zero in case of success and a
792 * negative error code in case of failure.
794 static int autoresize(struct ubi_device *ubi, int vol_id)
796 struct ubi_volume_desc desc;
797 struct ubi_volume *vol = ubi->volumes[vol_id];
798 int err, old_reserved_pebs = vol->reserved_pebs;
801 * Clear the auto-resize flag in the volume in-memory copy of the
802 * volume table, and 'ubi_resize_volume()' will propagate this change
805 ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
807 if (ubi->avail_pebs == 0) {
808 struct ubi_vtbl_record vtbl_rec;
811 * No available PEBs to re-size the volume, clear the flag on
814 memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
815 sizeof(struct ubi_vtbl_record));
816 err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
818 ubi_err("cannot clean auto-resize flag for volume %d",
822 err = ubi_resize_volume(&desc,
823 old_reserved_pebs + ubi->avail_pebs);
825 ubi_err("cannot auto-resize volume %d", vol_id);
831 ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
832 vol->name, old_reserved_pebs, vol->reserved_pebs);
837 * ubi_attach_mtd_dev - attach an MTD device.
838 * @mtd: MTD device description object
839 * @ubi_num: number to assign to the new UBI device
840 * @vid_hdr_offset: VID header offset
841 * @max_beb_per1024: maximum number of expected bad blocks per 1024 PEBs
843 * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
844 * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
845 * which case this function finds a vacant device number and assigns it
846 * automatically. Returns the new UBI device number in case of success and a
847 * negative error code in case of failure.
849 * Note, the invocations of this function has to be serialized by the
850 * @ubi_devices_mutex.
852 int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num,
853 int vid_hdr_offset, int max_beb_per1024)
855 struct ubi_device *ubi;
858 if (max_beb_per1024 < 0 || max_beb_per1024 > MAX_MTD_UBI_BEB_LIMIT)
861 if (!max_beb_per1024)
862 max_beb_per1024 = CONFIG_MTD_UBI_BEB_LIMIT;
865 * Check if we already have the same MTD device attached.
867 * Note, this function assumes that UBI devices creations and deletions
868 * are serialized, so it does not take the &ubi_devices_lock.
870 for (i = 0; i < UBI_MAX_DEVICES; i++) {
871 ubi = ubi_devices[i];
872 if (ubi && mtd->index == ubi->mtd->index) {
873 ubi_err("mtd%d is already attached to ubi%d",
880 * Make sure this MTD device is not emulated on top of an UBI volume
881 * already. Well, generally this recursion works fine, but there are
882 * different problems like the UBI module takes a reference to itself
883 * by attaching (and thus, opening) the emulated MTD device. This
884 * results in inability to unload the module. And in general it makes
885 * no sense to attach emulated MTD devices, so we prohibit this.
887 if (mtd->type == MTD_UBIVOLUME) {
888 ubi_err("refuse attaching mtd%d - it is already emulated on "
889 "top of UBI", mtd->index);
893 if (ubi_num == UBI_DEV_NUM_AUTO) {
894 /* Search for an empty slot in the @ubi_devices array */
895 for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
896 if (!ubi_devices[ubi_num])
898 if (ubi_num == UBI_MAX_DEVICES) {
899 ubi_err("only %d UBI devices may be created",
904 if (ubi_num >= UBI_MAX_DEVICES)
907 /* Make sure ubi_num is not busy */
908 if (ubi_devices[ubi_num]) {
909 ubi_err("ubi%d already exists", ubi_num);
914 ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
919 ubi->ubi_num = ubi_num;
920 ubi->vid_hdr_offset = vid_hdr_offset;
921 ubi->autoresize_vol_id = -1;
923 mutex_init(&ubi->buf_mutex);
924 mutex_init(&ubi->ckvol_mutex);
925 mutex_init(&ubi->device_mutex);
926 spin_lock_init(&ubi->volumes_lock);
928 ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
929 dbg_msg("sizeof(struct ubi_ainf_peb) %zu", sizeof(struct ubi_ainf_peb));
930 dbg_msg("sizeof(struct ubi_wl_entry) %zu", sizeof(struct ubi_wl_entry));
932 err = io_init(ubi, max_beb_per1024);
937 ubi->peb_buf = vmalloc(ubi->peb_size);
941 err = ubi_debugging_init_dev(ubi);
945 err = ubi_attach(ubi);
947 ubi_err("failed to attach mtd%d, error %d", mtd->index, err);
951 if (ubi->autoresize_vol_id != -1) {
952 err = autoresize(ubi, ubi->autoresize_vol_id);
957 err = uif_init(ubi, &ref);
961 err = ubi_debugfs_init_dev(ubi);
965 ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
966 if (IS_ERR(ubi->bgt_thread)) {
967 err = PTR_ERR(ubi->bgt_thread);
968 ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
973 ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
974 ubi_msg("MTD device name: \"%s\"", mtd->name);
975 ubi_msg("MTD device size: %llu MiB", ubi->flash_size >> 20);
976 ubi_msg("number of good PEBs: %d", ubi->good_peb_count);
977 ubi_msg("number of bad PEBs: %d", ubi->bad_peb_count);
978 ubi_msg("number of corrupted PEBs: %d", ubi->corr_peb_count);
979 ubi_msg("max. allowed volumes: %d", ubi->vtbl_slots);
980 ubi_msg("wear-leveling threshold: %d", CONFIG_MTD_UBI_WL_THRESHOLD);
981 ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
982 ubi_msg("number of user volumes: %d",
983 ubi->vol_count - UBI_INT_VOL_COUNT);
984 ubi_msg("available PEBs: %d", ubi->avail_pebs);
985 ubi_msg("total number of reserved PEBs: %d", ubi->rsvd_pebs);
986 ubi_msg("number of PEBs reserved for bad PEB handling: %d",
988 ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
989 ubi_msg("image sequence number: %u", ubi->image_seq);
992 * The below lock makes sure we do not race with 'ubi_thread()' which
993 * checks @ubi->thread_enabled. Otherwise we may fail to wake it up.
995 spin_lock(&ubi->wl_lock);
996 ubi->thread_enabled = 1;
997 wake_up_process(ubi->bgt_thread);
998 spin_unlock(&ubi->wl_lock);
1000 ubi_devices[ubi_num] = ubi;
1001 ubi_notify_all(ubi, UBI_VOLUME_ADDED, NULL);
1005 ubi_debugfs_exit_dev(ubi);
1007 get_device(&ubi->dev);
1012 ubi_free_internal_volumes(ubi);
1015 ubi_debugging_exit_dev(ubi);
1017 vfree(ubi->peb_buf);
1019 put_device(&ubi->dev);
1026 * ubi_detach_mtd_dev - detach an MTD device.
1027 * @ubi_num: UBI device number to detach from
1028 * @anyway: detach MTD even if device reference count is not zero
1030 * This function destroys an UBI device number @ubi_num and detaches the
1031 * underlying MTD device. Returns zero in case of success and %-EBUSY if the
1032 * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
1035 * Note, the invocations of this function has to be serialized by the
1036 * @ubi_devices_mutex.
1038 int ubi_detach_mtd_dev(int ubi_num, int anyway)
1040 struct ubi_device *ubi;
1042 if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
1045 ubi = ubi_get_device(ubi_num);
1049 spin_lock(&ubi_devices_lock);
1050 put_device(&ubi->dev);
1051 ubi->ref_count -= 1;
1052 if (ubi->ref_count) {
1054 spin_unlock(&ubi_devices_lock);
1057 /* This may only happen if there is a bug */
1058 ubi_err("%s reference count %d, destroy anyway",
1059 ubi->ubi_name, ubi->ref_count);
1061 ubi_devices[ubi_num] = NULL;
1062 spin_unlock(&ubi_devices_lock);
1064 ubi_assert(ubi_num == ubi->ubi_num);
1065 ubi_notify_all(ubi, UBI_VOLUME_REMOVED, NULL);
1066 dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
1069 * Before freeing anything, we have to stop the background thread to
1070 * prevent it from doing anything on this device while we are freeing.
1072 if (ubi->bgt_thread)
1073 kthread_stop(ubi->bgt_thread);
1076 * Get a reference to the device in order to prevent 'dev_release()'
1077 * from freeing the @ubi object.
1079 get_device(&ubi->dev);
1081 ubi_debugfs_exit_dev(ubi);
1084 ubi_free_internal_volumes(ubi);
1086 put_mtd_device(ubi->mtd);
1087 ubi_debugging_exit_dev(ubi);
1088 vfree(ubi->peb_buf);
1089 ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
1090 put_device(&ubi->dev);
1095 * open_mtd_by_chdev - open an MTD device by its character device node path.
1096 * @mtd_dev: MTD character device node path
1098 * This helper function opens an MTD device by its character node device path.
1099 * Returns MTD device description object in case of success and a negative
1100 * error code in case of failure.
1102 static struct mtd_info * __init open_mtd_by_chdev(const char *mtd_dev)
1104 int err, major, minor, mode;
1107 /* Probably this is an MTD character device node path */
1108 err = kern_path(mtd_dev, LOOKUP_FOLLOW, &path);
1110 return ERR_PTR(err);
1112 /* MTD device number is defined by the major / minor numbers */
1113 major = imajor(path.dentry->d_inode);
1114 minor = iminor(path.dentry->d_inode);
1115 mode = path.dentry->d_inode->i_mode;
1117 if (major != MTD_CHAR_MAJOR || !S_ISCHR(mode))
1118 return ERR_PTR(-EINVAL);
1122 * Just do not think the "/dev/mtdrX" devices support is need,
1123 * so do not support them to avoid doing extra work.
1125 return ERR_PTR(-EINVAL);
1127 return get_mtd_device(NULL, minor / 2);
1131 * open_mtd_device - open MTD device by name, character device path, or number.
1132 * @mtd_dev: name, character device node path, or MTD device device number
1134 * This function tries to open and MTD device described by @mtd_dev string,
1135 * which is first treated as ASCII MTD device number, and if it is not true, it
1136 * is treated as MTD device name, and if that is also not true, it is treated
1137 * as MTD character device node path. Returns MTD device description object in
1138 * case of success and a negative error code in case of failure.
1140 static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
1142 struct mtd_info *mtd;
1146 mtd_num = simple_strtoul(mtd_dev, &endp, 0);
1147 if (*endp != '\0' || mtd_dev == endp) {
1149 * This does not look like an ASCII integer, probably this is
1152 mtd = get_mtd_device_nm(mtd_dev);
1153 if (IS_ERR(mtd) && PTR_ERR(mtd) == -ENODEV)
1154 /* Probably this is an MTD character device node path */
1155 mtd = open_mtd_by_chdev(mtd_dev);
1157 mtd = get_mtd_device(NULL, mtd_num);
1162 static int __init ubi_init(void)
1166 /* Ensure that EC and VID headers have correct size */
1167 BUILD_BUG_ON(sizeof(struct ubi_ec_hdr) != 64);
1168 BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
1170 if (mtd_devs > UBI_MAX_DEVICES) {
1171 ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
1175 /* Create base sysfs directory and sysfs files */
1176 ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
1177 if (IS_ERR(ubi_class)) {
1178 err = PTR_ERR(ubi_class);
1179 ubi_err("cannot create UBI class");
1183 err = class_create_file(ubi_class, &ubi_version);
1185 ubi_err("cannot create sysfs file");
1189 err = misc_register(&ubi_ctrl_cdev);
1191 ubi_err("cannot register device");
1195 ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
1196 sizeof(struct ubi_wl_entry),
1198 if (!ubi_wl_entry_slab)
1201 err = ubi_debugfs_init();
1206 /* Attach MTD devices */
1207 for (i = 0; i < mtd_devs; i++) {
1208 struct mtd_dev_param *p = &mtd_dev_param[i];
1209 struct mtd_info *mtd;
1213 mtd = open_mtd_device(p->name);
1219 mutex_lock(&ubi_devices_mutex);
1220 err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
1222 CONFIG_MTD_UBI_BEB_LIMIT);
1223 mutex_unlock(&ubi_devices_mutex);
1225 ubi_err("cannot attach mtd%d", mtd->index);
1226 put_mtd_device(mtd);
1229 * Originally UBI stopped initializing on any error.
1230 * However, later on it was found out that this
1231 * behavior is not very good when UBI is compiled into
1232 * the kernel and the MTD devices to attach are passed
1233 * through the command line. Indeed, UBI failure
1234 * stopped whole boot sequence.
1236 * To fix this, we changed the behavior for the
1237 * non-module case, but preserved the old behavior for
1238 * the module case, just for compatibility. This is a
1239 * little inconsistent, though.
1241 if (ubi_is_module())
1249 for (k = 0; k < i; k++)
1250 if (ubi_devices[k]) {
1251 mutex_lock(&ubi_devices_mutex);
1252 ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
1253 mutex_unlock(&ubi_devices_mutex);
1257 kmem_cache_destroy(ubi_wl_entry_slab);
1259 misc_deregister(&ubi_ctrl_cdev);
1261 class_remove_file(ubi_class, &ubi_version);
1263 class_destroy(ubi_class);
1265 ubi_err("UBI error: cannot initialize UBI, error %d", err);
1268 module_init(ubi_init);
1270 static void __exit ubi_exit(void)
1274 for (i = 0; i < UBI_MAX_DEVICES; i++)
1275 if (ubi_devices[i]) {
1276 mutex_lock(&ubi_devices_mutex);
1277 ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
1278 mutex_unlock(&ubi_devices_mutex);
1281 kmem_cache_destroy(ubi_wl_entry_slab);
1282 misc_deregister(&ubi_ctrl_cdev);
1283 class_remove_file(ubi_class, &ubi_version);
1284 class_destroy(ubi_class);
1286 module_exit(ubi_exit);
1289 * bytes_str_to_int - convert a number of bytes string into an integer.
1290 * @str: the string to convert
1292 * This function returns positive resulting integer in case of success and a
1293 * negative error code in case of failure.
1295 static int __init bytes_str_to_int(const char *str)
1298 unsigned long result;
1300 result = simple_strtoul(str, &endp, 0);
1301 if (str == endp || result >= INT_MAX) {
1302 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1314 if (endp[1] == 'i' && endp[2] == 'B')
1319 printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
1328 * ubi_mtd_param_parse - parse the 'mtd=' UBI parameter.
1329 * @val: the parameter value to parse
1332 * This function returns zero in case of success and a negative error code in
1335 static int __init ubi_mtd_param_parse(const char *val, struct kernel_param *kp)
1338 struct mtd_dev_param *p;
1339 char buf[MTD_PARAM_LEN_MAX];
1340 char *pbuf = &buf[0];
1341 char *tokens[MTD_PARAM_MAX_COUNT];
1346 if (mtd_devs == UBI_MAX_DEVICES) {
1347 printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
1352 len = strnlen(val, MTD_PARAM_LEN_MAX);
1353 if (len == MTD_PARAM_LEN_MAX) {
1354 printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
1355 "max. is %d\n", val, MTD_PARAM_LEN_MAX);
1360 printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
1367 /* Get rid of the final newline */
1368 if (buf[len - 1] == '\n')
1369 buf[len - 1] = '\0';
1371 for (i = 0; i < MTD_PARAM_MAX_COUNT; i++)
1372 tokens[i] = strsep(&pbuf, ",");
1375 printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
1380 p = &mtd_dev_param[mtd_devs];
1381 strcpy(&p->name[0], tokens[0]);
1384 p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
1386 if (p->vid_hdr_offs < 0)
1387 return p->vid_hdr_offs;
1393 module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
1394 MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
1395 "mtd=<name|num|path>[,<vid_hdr_offs>].\n"
1396 "Multiple \"mtd\" parameters may be specified.\n"
1397 "MTD devices may be specified by their number, name, or "
1398 "path to the MTD character device node.\n"
1399 "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
1400 "header position to be used by UBI.\n"
1401 "Example 1: mtd=/dev/mtd0 - attach MTD device "
1403 "Example 2: mtd=content,1984 mtd=4 - attach MTD device "
1404 "with name \"content\" using VID header offset 1984, and "
1405 "MTD device number 4 with default VID header offset.");
1407 MODULE_VERSION(__stringify(UBI_VERSION));
1408 MODULE_DESCRIPTION("UBI - Unsorted Block Images");
1409 MODULE_AUTHOR("Artem Bityutskiy");
1410 MODULE_LICENSE("GPL");